Recently electrically controlled clutch assemblies have been designed. Such assemblies use an external source, such as an electric motor, to move a pressure plate into and out of engagement with a clutch disc. The use of an electric motor to move the pressure plate eliminates the need of a mechanical linkage between the clutch pedal and the clutch assembly. Such a system allows for the “free rolling” of the drive train which improves fuel economy by removing efficiency losses in an unpowered drive train (e.g. the transmission in the neutral position while in motion but not under power). As the system no longer requires the mechanical linkage between the clutch pedal and the clutch assembly, the system allows for an electronic or “fly-by-wire” type clutch pedal assembly.
In previously known electronic clutch pedal assembly a position sensor is used to sense the movement of the pedal arm to a position where the clutch would disengage to permit shifting. However, a significant drawback of these previously known electronic clutch pedal assemblies is that removal of the mechanical linkage between the pedal and the clutch assembly removes the resistance or “pedal feel” that a driver is typically accustomed to sense during clutch operation. As shown in FIG. 1, the dashed line L1 illustrates a force curve of a conventional clutch pedal assembly having a mechanical linkage between the clutch pedal and the clutch assembly. The conventional force curve rises slowly to a peak of about 50% of the travel path of the clutch pedal at which point the disengagement of the pressure plate with the clutch disc occurs. Upon the disengagement of the pressure plate with the clutch disc, the force curve tapers until the end of the travel path. Thus, it is desirable to provide an electronic clutch pedal assembly which provides a realistic “pedal feel” in which resistance rises until the disengagement point and resistance decreases after the disengagement point.